Earth moving vehicle dumping structure

ABSTRACT

A vehicle for excavating earth or other similar material and then transporting same to a site for dumping. The vehicle includes an open ended bowl construction comprised of a pair of side walls, a base wall and a rear wall arrangement. The base wall construction provides the floor area for supporting the earth material, and is defined by a pair of hingedly connected panels movable to an open condition so as to provide a pair of dumping openings on opposite sides thereof. The rear wall arrangement is provided by a rear panel member mounted for both vertical and retractive movement relative to the base wall construction. The vertical movement thus afforded permits the lower portion of the rear wall member to function as a spreader blade during dumping, while the retractive movement facilitates the overall dumping operation.

United States Patent [451 Aug. 1,1972

Scott [54.] EARTH MOVING VEHICLE DUMPING STRUCTURE [72] Inventor: ThomasH. Scott, Jackson, Miss.

' [73] Assignee: M-R-S Manufacturing Company,

Flora, Miss.

[22] Filed: March 2, 1970 [21] Appl. No.: 15,475

[52] U.S. Cl. ..37/129, 37/8, 37/126 AC [51] Int. Cl. ..E02f 3/02 [58]Field of Search ...37/l26, 129, 8

[56] References Cited UNITED STATES PATENTS 3,521,388 7/1970 Simmons..37/129 3,431,663 3/1969 Eiger ..37/126 R X 3,057,090 10/1962 Mazzarins..37/126 R 7 3,466,765 9/1969 Bernotas et a1 ..3 7/126 R X 3,235,9852/1966 Lauster ..37/126 3,108,388 10/1963 Johnson ..37/8 X 3,343,2869/1967 Ray et al ..37/8

Primary Examiner-Edgar S. Burr Attorney-Olson, Trexler, Wolters &Bushnell [5 7] ABSTRACT A vehicle for excavating earth or other similarmaterial and then transporting same to a site for dumping. The vehicleincludes an open ended bowl construction comprised of a pair of sidewalls, a base wall and a rear wall arrangement. The base wallconstruction provides the floor area for supporting the earth material,and is defined by a pair of hingedly connected panels movable to an opencondition so as to provide a pair of dumping openings on opposite sidesthereof. The rear wall arrangement is provided by a rear panel membermounted for both vertical and retractive movement relative to the basewall construction. The vertical movement thus afforded permits the lowerportion of the rear wall member to function as a spreader blade duringdumping, while the retractive movement facilitates the overall dumpingoperation.

25 Claims, 7 Drawing Figures PATENTEDMIB 1 m2 sum 1 or 3 EARTH MOVINGVEHICLE DUMPING STRUCTURE BACKGROUND OF INVENTION This invention relatesto earth moving machines, or the like, and more particularly to animproved bowl construction and mode of operation for a vehicle of thetype which planes earth from the surface of the ground and stores samein said bowl for subsequent dumping, wherein dumping is achieved throughthe bottom wall or floor of said bowl construction.

Conventional earth scraper and dumping apparatus of the general typeemploying a bottom wall dumping arrangement are known, such as thosedisclosed in US. Pat. No. 3,343,286, issued Sept. 26, 1967, and in U.S.application Ser. No. 685,009; now U. S. Pat. No. 3,521,388 filed Nov.22, 1967. With earth scraper machines such as these, an open bowlconstruction is provided into which earth fill or other materials areloaded. The forward, open end of the bowl has a scraper bladedecliningly mounted thereon, such that when it is desired to load thebowl, the front end thereof is lowered to bring said blade into contactwith the ground. Accordingly, as the scraper machine is moved forward bya tractor or some other towing apparatus, the blade cuts or planes intothe earth causing it to move upwardly into the bowl. In addition,elevator apparatus are often employed in conjunction with said open endof the bowl construction to facilitate the disposition of the earth orearth fill into said bowl.

While the various vehicles and scraper bowl constructions of the priorart, and especially those specifically mentioned above, have provensuccessful. There is an ever increasing demand for improved structures,that is, structures which are simpler to repair and operate, yet capableof performing in the same manner. or in an improved manner with respectto conventional machines. In this regard, by simplification of thestructural arrangement, numerous advantages can be obtained, forexample, more rugged, trouble-free operation; simplification ofmaintenance problems; and reduction in the overall cost of the vehicle.

The ejection arrangements of the prior art devices, with the exceptionof those taught in the above-mentioned patent and pending application,have not proven satisfactory due to the excessively large scraper bowlused, the intricate and rather costly provisions for unloading andleveling, and the reduction or limitation of available scraper bowlspace required for the dumping mechanism.

Accordingly, with the hereinafter to be discussed scraper bowlconstruction, many of the advantages obtainable with thestructures'discussed in the aforementioned patent and pendingapplication can be attained, while other, previously unattainableadvantages or improvements will also be realized. In this regard, thepresent invention provides a bowl construction employing a hingedlymounted rear wall that can be moved both rearwardly and downwardly ofthe base or bottom wall of the bowl construction to provide an initialdumping opening. The movement of the rear wall can be controlled withregard to both phases so as to vary the size of the initial opening thusproduced, and also to vary the degree of downward movement obtained.Concerning this latter point, the lower edge portion of the rear wallmay now be used as a spreader or grading blade, thus eliminating thenecessity for separate, intricate spreader blade attachments found onthe prior art constructions. Also, the present invention provides anovel single fold base wall arrangement and operating apparatus, all ofwhich cooperate to assure that the dumping openings obtainable therewithare properly positioned with respect to the bowl construction so as toassure and facilitate complete dump- Further, concerning the overallarrangement of the bowl construction of the present invention, it shouldbe noted that same is designed such that during dumping the movement ofall articulated elements is away from any surface or stationary elementagainst which the earth material can be compressed. In this regard,quite often the earth fill is moist and sticky such that when compressedit will adhere to the surfaces of the bowl, so as to hinder and resistcomplete ejection from the bowl construction.

The employment of the rear wall arrangement of the present invention issuch that the use of a separate grader or leveling attachment, as foundon the prior art structures, is eliminated. Thus, the various intricateand costly operating mechanisms employed with the aforementionedseparate grader attachments are also done away with, this being donewithout sacrificing the overall performance of the vehicle. In addition,with the single fold type of base wall arrangement of the presentinvention, approximately percent of the original, material supportingfloor area is removed during the dumping, so as to afford the largestpossible dumping opening.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT FIG. I is a side view of anearth moving vehicle of the present invention, which vehicle is designedto be drawn by a tractor, or the like;

FIG. 2 is a sectional view of the earth moving vehicle of FIG. 1illustrating the disposition of the vehicle during loading of earth fillmaterial into the bowl construction;

FIG. 3 is a sectional view similar to FIG. 2 and showing the manner inwhich the rear wall of the bowl construction operates to provide theinitial dumping open- FIG. 4 is a sectional view similar to FIGS. 2 and3 and illustrating how the rear wall may be employed as a spreader, andalso illustrating the operation of the novel single fold base wall ofthe present invention;

FIGS. 5 and 6 are enlarged, fragmentary sectional views of the rear wallarrangement of the present invention and the operating mechanismemployed therewith, and illustrating how said wall is retracted and thenlowered;

- FIG. 7 is a fragmentary sectional view illustrating the employment ofadjustable stop means for regulating the retractive movement of the rearwall.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT construction 20 by a hingeconnection designated generally 22. A pair of power cylinders 24 areprovided, each being carried by a side arm 18 or the cross member 16 andhaving their respective actuator rods 26 pivotally connected to the bowl20 proximate the front edge of said bowl and on opposite sides thereof.Accordingly, operation of the power cylinders 24 is effective to raiseand lower the bowl 20 between the position illustrated in FIG. 1 andthat of FIG. 2. Concerning the latter, it can be seen that uponextension of the actuator rods 26, a scraper blade 30 is brought intoposition for engagement with the soil in preparation for the loadingoperation.

In addition to the scraper blade 30, the bowl construction 20 furtherincludes a rear frame segment 32 which supports a rear wheel arrangement34, a pair of spaced side walls 36, a base or bottom wall construction38 disposed intermediate said side walls 36 and defining the materialsupporting floor area, and a rear wall 40. Thus, it can be seen thatthere is provided an open ended structure having a scooplikeconfiguration, which is adapted to contain a substantial quantity ofearth fill, sand, gravel, or the like.

The aforementioned pivotal connection of the actuator arms 26 to thebowl 20 is effected adjacent the open front end of the bowl, andproximate the base wall construction 38. While the base wallconstruction 38 will be described in more detail hereinafter regardingthe operation of the scraper vehicle 10, it can be seen from FIG. 2 thatthe aforementioned scraper blade 30 defines the forward edge portionthereof.

In the illustrated embodiment, the leading or forward edges of the sidewalls 36 are formed at an acute angle with respect to the base wallconstruction 38. The slope of these edges is not critical with respectto the present invention, and they are disposed on a bias primarily toaccommodate an elevator structure 42.

The elevator structure 42 is operatively positioned with respect to theopen forward end of bowl 20 by attachment to the spaced side walls 36.Numerous articulated mounting systems for elevators of this type areknown in the art, such as that illustrated in the aforementioned pendingapplication. Accordingly, it is envisioned that any of these may beemployed with the vehicle of the present invention; or for that matter,a stationary mounting arrangement may be utilized. Irrespective of thespecifics concerning the mounting of elevator 42, or its drive mechanism(not shown), said elevator 42 is comprised primarily of a plurality ofspaced apart, horizontally positioned material engaging slats or angleirons 44 carried by a pair of sprocket chains 46 engaged over upper andlower sprocket gear assemblies 47 and 48. Each sprocket gear assembly isof conventional construction and includes an axle, 49, 50, with a pairof laterally spaced sprocket gears carried on the opposite ends thereof.Accordingly, upon the application of a driving force to one or the otherof said axles 49 or 50 by said drive mechanism (not shown), the sprocketchains 46 and the material engaging slats 44 attached thereto, will bedriven in the direction indicated by arrow 52.

Considering now specifically FIG. 2, and the heretofore describedconstruction of the vehicle 10, a brief summary of the manner ofoperation of the vehicle 10 during loading will now be given. Initially,the bowl 20 will be in the raised position as shown in FIG. 1. When theoperator reaches the location wherein earth removal is to take place,and upon the proper positioning of the vehicle 10 with respect thereto,the power cylinders 24 are employed to extend the actuator rods 26 whichcause the bowl 20 to pivot about an axis provided by the rear wheelarrangement 34. This pivoting movement lowers the forward edge of thebowl construction 20 bringing the scraper blade 30 into contact with thesoil. Thus, as the vehicle 10 is pulled forward by the tractor 12, theblade 30 will plane or cut into the soil with the severed materialmoving upwardly into the interior of the bowl 20. During this loadingprocedure, the elevator 42 is actuated to produce movement as mentionedpreviously which, due to the positioning of the lower end of theelevator 42 proximate the blade 30, facilitates thedisposition of earthinto the bowl 20, as well as advancement of said earth toward the rearwall 40. When the bowl construction 20 is filled, the operator utilizesthe power cylinders 24 to retract the actuator rods 26 raising the bowlso as to preclude spillage of the earth from the open forward endthereof. The vehicle 10 is then towed to a dumping site where thematerial in bowl 20 is expelled or ejected, and then graded and rolled.

The general or overall construction of the vehicle 10 described to thispoint, as well as its manner of operation during loading, areconventional features which may be found in the prior art structures.These features have been set forth, however, not only as backgroundmaterial, but to afford a more complete understanding and appreciationof the contribution to the art realized with the present invention.Primarily, the present invention relates to a novel bowl structure whichfacilitates the dumping operation and provides a vehicle that is of amore simplified, economical and rugged construction than those of theprior art, yet is capable of improved performance in service, ascompared with said prior art vehicles. In addition, the presentinvention also relates to a novel dumping method that materiallyincreases the operational efficiency of the vehicle.

More specifically, the present invention is concerned with two facets orfeatures of the general construction of bowl 20; namely, that of therear wall 40 and the base wall construction 38. Each of these featuresprovides numerous advantages over the prior art when employedseparately; however, their combination in a single' vehicle also affordsadvantages previously unattainable with the prior art structures.

Before discussing in detail the mode of operation of the aforementionedfeatures of the present invention, it is believed advantageous to firstset forth the preferred structural arrangements of each with respect tothe illustrated embodiment.

Attention is first directed to the arrangement of the base wallconstruction 38, and more specifically FIGS. 2-4. In this regard, theoverall base wall construction 38 is comprised of the previouslymentioned scraper blade 30 which defines the leading edge thereof, and apair of panels 54 and 56 hingedly connected to each other along adjacentedges. When the base wall construction 38 is in the closed, materialsupporting condition, FIGS. 2 and 3, the free edge of the forwardmostpanel 54 is disposed adjacent the scraper blade 30, while the free edgeof the rearward panel 56 abuts the rear wall 40. The hinged connectionfor the adjacent edges of said panel is designated generally 58, and isdisposed substantially in the middle of the floor area, thus provided bythe base wall construction 38.

On opposite sides of each said panel 54 and 56, proximate the free endsthereof, there are provided apertured brackets 60 disposed interiorly ofthe bowl side walls 36. Rotatably engaged with each pair of brackets 60is an elongate rod or pin element 62 that extends laterally beyond thelower edges of the side walls 36. With reference to FIG. 1, bearingcarriages 64 are journalled to each end of the respective rod elements62 at a location exteriorly of the side walls 36. Each bearing carriage64 includes one or more rollers 66 disposed in rolling contact with atrack 68 formed on the adjacent exterior surface of the associated sidewall 36. Thus, it can be seen that the panels 54 and 56 are mounted forhinged articulated movement, with the movement of the free edgesrelative to side walls 36 being confined to a path defined by therespective tracks 68.

To provide for operation of the base wall construction 38 from theclosed condition of FIGS. 2 and 3 to the open condition as shown in FIG.4, a pair of drive arrangements are employed, each designated generally70. One such arrangement 70 is utilized on each side of the vehicle. Inthis regard, a pair of brackets 72 are attached to panel 56, adjacentthe hinge connection 58, with one being disposed on each side thereof.Pivotally connected to each said bracket 72 is a bell crank 74 which isin turn operatively connected to a power cylinder 76 mounted exteriorlyof the vehicle on the associated side wall 36. The respective bellcranks 74 are journalled in apertures formed in the side walls 36, andeach includes an arm element 78 disposed interiorly of the bowl and anarm element 80 disposed exteriorly of the bowl. The actuating rods 82 ofthe power cylinders 76 are operatively connected to the arm elements 80of their respective bell cranks 74, such that upon extension of saidrods 82 the bell cranks 74 will rotate in a clockwise direction, asindicated by arrow 84 in FIGS. 2 and 3.

The movement of the base wall construction 38 from the closed conditionof FIGS. 2 and 3 to the open condition of FIG. 4 will now be considered.As the respective power cylinders 76 on each side of the vehicle areoperated to rotate the bell cranks 74 in a clockwise direction, theinteriorly disposed arm elements 78, as well as the hinged connection 58move upwardly. With the actuator rods 82 completely extended, the panels54 and 56 will assume the position illustrated in FIG. 4, such that apair of dumping openings are provided on opposite sides of said panels.It should be noted in this regard, that the confining of the movement ofthe free edges of panels 54 and 56 to a linear path, taken inconjunction with the drive arrangements 70 which confine movement of thehinge connection 58 to a substantially vertical path, insure that thepanels 54 and 56 will assume the positioning of FIG. 4, wherein they aredisposed approximately in the middle of the material supporting floorarea of bowl 20.

Accordingly, with the unique and novel single-fold base wallconstruction 38, and the particular mode of operation afforded by thedrive arrangements 70, the maximum amount of floor area is removed indefining the dumping openings. In practice, approximately percent of theeffective load supporting area is removed which greatly facilitates andassures complete dumping.

Attention is now directed to a consideration of the rear wall 40, itsmode of operation, and the particular operating structure of thedisclosed embodiment employed in effecting said mode of operation. Aswill be recalled from the prior discussion, the rear wall 40 is mountedfor regulated downward movement relative to the base wall 38 so as toadapt the lower portion thereof to function as a spreader or levelingblade-a feature which permits the elimination of the separate spreaderattachments of the prior art constructions. In addition, the rear wall40 is also designed for controlled retractive movement as will bedetailed more completely hereinafter.

Looking to FIG. 2, the rear wall 40 is shown in the closed position withits lower edge portion abutting the adjacent free edge of the base wallconstruction 38 to close the rear portion of bowl 20. The rear wall 40is mounted with respect to the rearward frame portion 32 by means of alink element 92. While one such link element is shown, any number may beemployed as desired or required.

With reference to FIGS. 5 and 6, the link element 92 is pivotallyconnected to the rear wall 40 by a first hinge connection 94 and to therear frame portion 32 by a second hinge connection 96 disposed below theconnection 94. Accordingly, the wall 40 is free to move relative to theside walls 36 and the base wall construe tion 38 by pivoting about theconnection 96 to the rear frame portion 32.

In addition, a power cylinder 100 is provided for operating the rearwall 40. The power cylinder 100 is carried by the frame 32 and has itsactuating rod 102 connected to the link element 92 at a point 104disposed below the aforementioned connections 94 and 96. The lowerportion of the link element 92 disposed adjacent the point of connection104 is not physically attached to the rear wall 40 but in effectprovides an abutment surface 106 against which said wall is engaged.Thus, upon extension of the actuating rod 102, as shown in FIG. 2, therear wall 40 and link element 92 will pivot about the connection 96 tobring the lower portion 90 of said wall into abutting engagement withthe free edge of the base wall construction 38.

When it is desired to initiate the dumping cycle for the vehicle 10, thepower cylinder 100 is employed to retract the actuating rod 102. Withreference to FIGS. 3 and 5, due to the weight of the earth fill bearingagainst the rear wall 40, said wall will remain in engagement with theabutting surface 106, causing same to pivot rearwardly about theconnection 96 from the position illustrated in dotted outline to thatshown in full line. When this occurs, an elongate opening will be formedbetween the lower portion 90 of the rear wall and the free edge of panel56 which permits initial dumping of the earth fill, as shown in FIG. 3.

Considering now specifically FIG. 5, the full line position of the rearwall 40 as shown, corresponds to I that of FIG. 3. In this regard, itcan be seen that the lower portion 90 of the rear wall 40 will moverearwardly until it abuts against a crossbrace element 110 of the rearframe portion 32. This crossbrace 1 10 in effect provides stop meanswhich limit the retractive movement of the rear wall 40 away from thefree edge of panel 56.

Looking now to FIG. 6, upon the further retraction of the actuating rod102, the abutment surface 106 formed on the lower portion of the link 92will move out of engagement with the rear wall 40. As retraction of thelower segment of link 92 continues,.link 92 will pivot about the pointof connection 96 with frame 32, as well as the point of connection 94with the rear wall 40, causing the rear wall 40 to pivot forwardlyslightly about the point of engagement with brace 110, and to movedownwardly. The downward movement afforded by this action results in alowering of the entire rear wall 40, so as to vary the position of thelower portion 90 with respect to. the vehicle 10. Thus, it can be seenthat after the rear wall 40 engages the stop means, the

' condition as shown in FIG. 5, the relative disposition of the loweredge portion 90 thereof can be adjusted anywhere between the positionsshown inFIG. Sand that of FIG. 6 by operation of the power cylinder 100.Accordingly, this lower wall portion is now available for use as aspreader blade to grade the material being dumped from bowl 20 asvehicle 10 moves forward.

In FIG. 7, there is illustratedan arrangement which may be employed toprovide for control of the retractive movement of wall 40, such that thesize or extent of the opening thus formed may be selected as desired. Itwill be recalled, that with the structures of FIGS. 5 and 6 retractivemovement will continue until the rear wall 40 engages the crossbrace110. Accordingly, by the employment of insert elements 112 of varioussizes which are engaged over the brace 110, the degree of retractivemovement and the size of the resulting opening formed by rear wall 40can be regulated as desired.

With the above-separate discussions of the construction of base wall 38and the rear wall arrangement 40 in mind, and with reference to FIGS.2-4, one mode of operation for the vehicle 10 will now be considered.However, before entering into this discussion, it should be noted thatthe hereinafter to be discussed mode of operation is but a preferredone, and that others may be relied upon. Accordingly, it is envisionedthat either the base wall 38 or the rear wall arrangement 40 can beoperated separately, as well as jointly, or the joint operation employedmay vary from that discussed hereinafter, the particular sequence ofoperation to be used depending upon the conditions encountered inservice.

Considering now primarily FIGS. 2-4, once the bowl is completely filled,as mentioned previously, the vehicle 10 is towed or pulled to a dumpingarea. When the vehicle 10 is positioned to the operators satisfaction,the power cylinder 100 is energized to commence retractive movement ofthe rear wall 40 away from the free edge of panel 56. This retractivemovement, as indicated in F IG.'3, provides an initial dumping openingthrough which material is expelled. However, the size of this openingwhich may be adjusted as mentioned with regard to FIG. 7, isinsufficient to achieve complete emptying of the bowl construction. Theretraction of the rear wall 40 continues until the lower portion thereofabuts the crossbrace 110, or one of the adaptors 112 of FIG. 7. Thismovement causes the upper portion of the rear wall 40 to move forwardand slightly downwardly of the load, with the illustrated wiper arms 114scraping the interior surfaces of the bowl side walls 36 to loosen anymaterial that may have stuck thereto.

Next, at the operators option, the rear wall 40 may be lowered so as toproperly position the lower portion 90 thereof for the spreading orgrading of the earth fill material to be dumped. In this regard, therelative positioning, or height, of the lower portion 90 may be adjustedas desired by controlling the extent of retraction of the actuator rod102.

The operation of the base wall construction 38 may take place at anytime, that is, either before or after actuation of the rear wall 40, andeven separately of said rear wall. In this regard, the initiation of theoperation of base wall construction 38 may be performed automatically ormanually by use of the overall control mechanism of vehicle 10 (notshown). In either instance, the power cylinders 76 are energized toextend actuator rods 82, thus rotating the bell cranks 74 in theclockwise direction to slide the panels 54 and 56 from the closedcondition to the open condition.

Immediately upon commencement of the operation of the base wallconstruction 38, the operator will move the vehicle 10 forward tofacilitate dumping, with the lower portion 90 of the rear wall 40functioning as a spreader or grader attachment to level the materialbeing dumped. The completely open condition for the base wallconstruction 38 is illustrated in FIG. 4, and it can be seen that alarge portion of the originallyavailable floor area supporting the earthfill has now been removed.

Regarding the operation of the base wall construction, it can be seenthat due to the particular manner of actuating the base wallconstruction and the mounting of the panels 54 and 56 to the side walls,the folded structure thus resulting is disposed substantially in themiddle of the originally available floor area with dumping openingsbeing provided on the opposite sides thereof. Also, it should be notedthat panels 54 and 56, and the rear wall 40 during operation to the opencondition, move-away from the elevator structure 42, or any surfacesagainst which earth fill material can be compressed, so as to precludeadhesion of this material to bowl 20 and to facilitate the expellingthereof under the influence of gravity.

In conclusion, it is seen from the above description of the inventionand the enumeration of certain of the results achieved, that there isprovided a novel vehicle structure of rather simple, troublefree, ruggedconstruction. While one specific embodiment of the present invention hasbeen described above and illustrated in the drawings, it is envisionedthat those skilled in the art may make various modifications,alterations or substitutions with regard to the mode of operation andthe specific elements, parts, or the like, so discussed; said changesbeing effected without departing from the spirit and scope of theinvention, which is defined by the claims appended hereto.

What is claimed is:

1. In a vehicle for transporting earth or other material, a scraper bowlconstruction having an open front end, and comprising: means defining apair of spaced side walls; a rear wall arrangement operativelypositioned relative to said side walls for closing a rear end portion ofthe bowl; and means defining a base wall for supporting said earth andother materials, and including relatively movable structure operativefrom a closed condition to an open condition wherein at least onedumping opening is provided; the improvement wherein said rear wallarrangement comprises; a rear wall member mounted for vertical movementrelative to said side walls and said base wall, and said rear wallmember including blade means defined by the lower portion thereof andadapted for the grading and spreading of material emptied from saidbowl, and operating means for effecting selective vertical movement ofsaid rear wall member so that the operating level of said blade meansmay be adjusted as desired.

2. A scraper bowl construction as defined in claim 1 wherein said rearwall arrangement further includes means providing for movement of saidrear wall member rearwardly away from said base wall, to provide anopening through which material may be dumped.

3. A scraper bowl construction as defined in claim 2 wherein saidoperating means includes means for effecting both said rearward and saidvertical movement of the rear wall member.

4. A scraper bowl construction as defined in claim 2, further includingcontrol means for selectively effecting either joint or separatemovement of said rear wall member and said relatively movable base wallstructure.

5. A scraper bowl construction as defined in claim 4 wherein saidcontrol means includes means efi'ecting movement of said rear wallmember prior to the initiation of movement of said base wall structure.

6. A scraper bowl construction as defined in claim 2, wherein said meansproviding for rearward movement of the rear wall member includes meansmounting said rear wall member for pivotal movement relative to saidbase wall and said side walls.

7. A scraper bowl construction as defined in claim 2, further comprisingstop means against which said rear wall member will engage to limit saidrearward movement, and said operating means including; at least onepower cylinder having a reciprocal rod element, and an elongate bracketmember pivotally connected to said rear wall member at a first point andto said rod element at a second point disposed below said first point,said bracket member further being pivotally connected to said bowlconstruction at a third point intermediate said first and second points,such that upon retraction of said rod element, the wall member willpivot rearwardly about said third point until the lower portion thereofengages said stop means, with continued retractive movement of said rodelement causing the entire rear wall member to move vertically such thatthe lower portion thereof may be employed in the grading of the materialto be dumped.

8. A scraper bowl construction as defined in claim 2, further includingstop means against which said rear wall will engage to define the limitof its rearward movement away from said base wall structure, said stopmeans being adjustable to vary the size of the opening thus producedupon said rearward movement.

9. A scraper bowl construction as defined in claim 1, wherein saidrelatively movable base wall structure comprises: a pair of panelmembers, said members being hingedly connected along adjacent edges, andhaving the opposed free edges thereof disposed proximate the rear wallmember and the open front end portion of the bowl, respectively; meansslidably connecting said panels to the side walls proximate the freeedges thereof; and operating means connected to the rearwardmost panelfor moving said hingedly connected panel edges upwardly with said freeedges moving toward each other thereby providing a pair of dumpingopenings.

10. In combination, a vehicle for transporting earth or other similarmaterial, said vehicle including a scraper bowl construction having anopen front end portion facilitating the loading of material therein;said bowl construction comprising: a pair of spaced apart side walls; abase wall intermediate said side walls for supporting said material, andincluding means for providing at least one dumping opening for theemptying of material from said bowl construction; and a rear walloperatively positioned relative to said side walls and said base wallfor closing the rear end portion of said bowl; the improvementcomprising: blade means carried by the lower portion of said rear wall,and means mounting said rear wall for vertical movement relative to saidside walls so as to permit the positioning of said blade means for thegrading of material being dumped from said bowl.

11. The combination as defined in claim 10 wherein said means mountingthe rear wall for vertical movement further include means permittingretractive movement of at least the lower portion of said rear wallrelative to the base wall so as to provide a space along therearwardmost edge of the base wall through which material may beexpelled from said bowl construction.

12. The combination as defined in claim 11 wherein said bowlconstruction includes a rear frame portion, and said means for mountingthe rear wall for vertical and retractive movement comprises: stop meansagainst which said rear wall engages to limit said retractive movement;drive means carried by said rear frame portion; and link means pivotallyconnected to said rear wall, said frame and said drive means, thepivotal connection to said rear wall being at a first location with theconnection to said drive means being at a second location disposed belowsaid first location and said pivotal connection of the link means to theframe being at a third location intermediate said first and secondlocation, such that said drive means will produce vertical movement uponoperation thereof by pivoting said rear wall rearwardly about thepivotal connection of said link to the frame until said rear wallengages said stop means with further operation of said drive meanscausing said rear wall to move vertically downwardly.

13. The combination as defined in claim 12, wherein said stop means isadjustable to control the retractive movement of said rear wall.

14. The combination as defined in claim 10 further including meansmounting said rear wall for pivotal movement about an axis disposedintermediate the upper end lower edges thereof, such that the portion ofthe rear wall above said axis pivots forwardly and downwardly while thatportion below said axis moves rearwardly away from the base wall toprovide a dumping opening immediately below material engaged againstsaid rear wall, with said forward and downward movement of the portionof the rear wall above said axis tending to initiate dumping of materialfrom said dumping.

15. The combination as defined in claim 14, wherein a portion of thebase wall includes blade elements which facilitate initiation of thedumping operation, as well as scrape the interior surfaces of said sidewalls.

16. A scraper bowl construction for use with a vehicle of the generaltype employed in the transporting of earth or other similar materials,said bowl construction being open at the front end portion thereof tofacilitate loading and comprising: a pair of spaced apart side walls; abase wall arrangement intermediate said side wall for supporting saidmaterial, said base wall arrangement including means for selectivelyproviding a dumping opening therein adjacent the rearward portion ofsaid bowl; and rear wall means closing the rear portion of said bowl,and including a rear wall member disposed between said side walls havinga lower portion thereof positioned adjacent a rear edge of said basewall arrangement when both are in a closed condition, and means foreffecting selective movement of said rear wall member rearwardly anddownwardly with respect to said side walls and said base wall arrangement to define an open condition for said rear wall means, wherein saidlower portion of said rear wall is positionable at selected levels foruse in the grading of material being emptied from said bowl.

- 17. In a vehicle for transporting earth or other similar material, ascraper bowl construction having an open forward end portion throughwhich material is loaded and comprising: a pair of spaced side walls, arear wall disposed intermediate said side walls to close the rearwardend portion of said bowl; and base wall structure for supporting saidmaterial, said base wall including first and second panel members,having oppositely disposed free edges and adjacent edges, hingedlyconnected together, the free edge of said second panel member beingdisposed forwardly toward said open end portion of the bowl with thefree edge of said first panel member being disposed rearwardly towardsaid rear wall when said base wall is in a closed condition,

, such that'said panel members provide flat surfaces for supportingmaterial in said bowl; means slidably connecting said first and secondpanels to said side walls proximate the free edges thereof; andoperating means for moving said panels from the closed condition to anopen condition by moving each said free edge relative to said side wallsand toward each other while the bingedly connected edges of said panelsmove upwardly, to provide dumping openings on opposite sides of saidpanels when in the open condition.

18. A scraper bowl construction as defined in claim 17, wherein saidoperating means include a pair of bell crank arrangements journalled tothe respective side walls of said bowl construction, each said bellcrank arrangement including a pair of arm elements, one said arm elementbeing disposed exteriorly of the associated side wall and the otherinteriorly thereof, said interiorly disposed arm elements beingconnected to one of said panel members proximate the hingedly connectededges, and said exteriorly disposed arm elements being operativelyconnected to a driven reciprocal member for producing rotative movementof said bell crank, which movement effects the operation of said panelmember.

19. A scraper bowl construction as defined in claim 17, wherein saidmeans slidably connecting said panels to said side walls, includes trackmeans carried by said side walls, an elongate rod element carried byeach side panel, a pair of carriage members rotatably engaged to theopposed ends of each rod element exteriorly of said side walls, andbearing means carried by each said carriage member in rolling engagementwith said track means.

20. A scraper bowl construction as defined in claim 17, furtherincluding blade means on a lower portion of said rear wall and meansmounting said rear wall for retractive and vertical movement away fromthe rear edge of the base wall structure, such that said verticalmovement will dispose said blade means for engagement with materialbeing dumped from said bowl.

21. A scraper bowl construction for use with the vehicle of the generaltype employed in the transportation of earth or other similar materials,said bowl construction being open at the front end thereof to facilitateloading and comprising: a pair of spaced apart side walls; a base wallarrangement intermediate said side walls for supporting said material,said base wall including first and second panel members having adjacentedges hingedly connected together with the remote edges of said panelsbeing slidably mounted to tracks on said side walls, and means foroperating said panels from a closed, material supporting condition withsaid remote edges positioned toward the front and rear bowl portions,respectively, to an open condition by moving said remote edges towardeach other while said adjacent hinged edges are moved upwardly, suchthat in the open condition, a pair of dumping openings are provided onopposite sides of said panel; and rear wall means including a rear wallmember closing the rear portion of said bowl construction and having alower portion thereof positioned adjacent the remote edge of therearwardmost panel of said base wall when said base wall arrangement andsaid rear wall means are both in the closed condition, and means foreffecting selective movement of said wall member rearwardly anddownwardly with respect to said side walls and said base wallarrangement to define an open condition for said rear wall means,wherein said lower portion of the wall member is positionable atselected levels for use in grading of material being emptied from saidbowl.

22. A method of dumping earth or other material from a scraper bowl,which bowl is of a type including a pair of spaced side walls, base wallstructure comprised of a pair of panels having adjacent edges hingedlyconnected together and remote edges slidable longitudinally relative tosaid side walls, said remote edges being disposed toward the forward andrear bowl portions respectively, when in the closed condition, and arear wall section mounted for retractive movement from a closedcondition with its lower portion disposed adjacent the rearwardmostpanel edge to an open condition; said method comprising the steps of:first moving said rear wall section rearwardly away from said base wallto provide a space defined by the rearward edge of the base wall and thelower portion of said rear wall, through which material may be initiallyemptied from said bowl; and then moving both said remote edges of thebase wall panels relative to said side walls and toward each other,while simultaneously moving said hingedly connected edge portionsupwardly to define a pair of base wall dumping openings through whichthe remaining material in said bowl construction can be emptied.

23. A method as defined in claim 22 wherein said step of moving the rearwall section rearwardly includes the step of moving said sectiondownwardly with respect to said sidewalls to dispose the lowermostportion thereof in position for grading the material dumped from saidbowl.

24. A method as defined in claim 23 wherein the mounting of said rearwall is achieved with a link arrangement pivotally connected to saidrear wall and a rear frame portion of the bowl construction, thusdefining a fixed and a floating pivot, and said steps of moving the rearwall section rearwardly and downwardly include the step of firstpivoting said wall section and said link arrangement about the fixedpivot to cause the lower portion thereof to move away from the basewall, engaging said lower section against stop means to preclude furtherretractive movement and then effecting relative pivotal movement betweensaid link arrangement and said wall member about said floating pivot tocause the entire wall member to move downwardly.

25. A method as defined in claim 24, wherein said steps of moving thewall section rearwardly and downwardly include the step of applying aretracting force to said link arrangement at a location disposed belowboth said fixed and said floating pivots.

1. In a vehicle for transporting earth or other material, a scraper bowlconstruction having an open front end, and comprising: means defining apair of spaced side walls; a rear wall arrangement operativelypositioned relative to said side walls for closing a rear end portion ofthe bowl; and means defining a base wall for supporting said earth andother materials, and including relatively movable structure operativefrom a closed condition to an open condition wherein at least onedumping opening is provided; the improvement wherein said rear wallarrangement comprises; a rear wall member mounted for vertical movementrelative to said side walls and said base wall, and said rear wallmember including blade means defined by the lower portion thereof andadapted for the grading and spreading of material emptied from saidbowl, and operating means for effecting selective vertical movement ofsaid rear wall member so that the operating level of said blade meansmay be adjusted as desired.
 2. A scraper bowl construction as defined inclaim 1 wherein said rear wall arrangement further includes meansproviding for movement of said rear wall member rearwardly away fromsaid base wall, to provide an opening through which material may bedumped.
 3. A scraper bowl construction as defined in claim 2 whereinsaid operating means includes means for effecting both said rearward andsaid vertical movement of the rear wall member.
 4. A scraper bowlconstruction as defined in claim 2, further including control means forselectively effecting either joint or separate movement of said rearwall member and said relatively movable base wall structure.
 5. Ascraper bowl construction as defined in claim 4 wherein said controlmeans includes means effecting movement of said rear wall member priorto the initiation of movement of said base wall structure.
 6. A scraperbowl construction as defined in claim 2, wherein said means providingfor rearward movement of the rear wall member includes means mountingsaid rear wall member for pivotal movement relative to said base walland said side walls.
 7. A scraper bowl construction as defined in claim2, further comprising stop means against which said rear wall memberwill engage to limit said rearward movement, and said operating meansincluding; at least one power cylinder having a reciprocal rod element,and an elongate bracket member pivotally connected to said rear wallmember at a first point and to said rod element at a second pointdisposed below said first point, said bracket member further beingpivotally connected to said bowl construction at a third pointintermediate said first and second points, such that upon retraction ofsaid rod element, the wall member will pivot rearwardly about said thirdpoint until the lower portion thereof engages said stop means, withcontinued retractive movement of said rod element causing the entirerear wall member to move vertically such that the lower portion thereofmay be employed in the grading of the material to be dumped.
 8. Ascraper bowl construction as defined in claim 2, further including stopmeans against which said rear wall will engage to define the limit ofits rearward movement away from said base wall structure, said stopmeans being adjustable to vary the size of the opening thus producedupon said rearward movement.
 9. A scraper bowl construction as definedin claim 1, wherein said relatively movable base wall structurecomprises: a pair of panel members, said members being hingedlyconnected along adjacent edges, and having the opposed free edgesthereof disposed proximate the rear wall member and the open front endportion of the bowl, respectively; means slidably connecting Said panelsto the side walls proximate the free edges thereof; and operating meansconnected to the rearwardmost panel for moving said hingedly connectedpanel edges upwardly with said free edges moving toward each otherthereby providing a pair of dumping openings.
 10. In combination, avehicle for transporting earth or other similar material, said vehicleincluding a scraper bowl construction having an open front end portionfacilitating the loading of material therein; said bowl constructioncomprising: a pair of spaced apart side walls; a base wall intermediatesaid side walls for supporting said material, and including means forproviding at least one dumping opening for the emptying of material fromsaid bowl construction; and a rear wall operatively positioned relativeto said side walls and said base wall for closing the rear end portionof said bowl; the improvement comprising: blade means carried by thelower portion of said rear wall, and means mounting said rear wall forvertical movement relative to said side walls so as to permit thepositioning of said blade means for the grading of material being dumpedfrom said bowl.
 11. The combination as defined in claim 10 wherein saidmeans mounting the rear wall for vertical movement further include meanspermitting retractive movement of at least the lower portion of saidrear wall relative to the base wall so as to provide a space along therearwardmost edge of the base wall through which material may beexpelled from said bowl construction.
 12. The combination as defined inclaim 11 wherein said bowl construction includes a rear frame portion,and said means for mounting the rear wall for vertical and retractivemovement comprises: stop means against which said rear wall engages tolimit said retractive movement; drive means carried by said rear frameportion; and link means pivotally connected to said rear wall, saidframe and said drive means, the pivotal connection to said rear wallbeing at a first location with the connection to said drive means beingat a second location disposed below said first location and said pivotalconnection of the link means to the frame being at a third locationintermediate said first and second location, such that said drive meanswill produce vertical movement upon operation thereof by pivoting saidrear wall rearwardly about the pivotal connection of said link to theframe until said rear wall engages said stop means with furtheroperation of said drive means causing said rear wall to move verticallydownwardly.
 13. The combination as defined in claim 12, wherein saidstop means is adjustable to control the retractive movement of said rearwall.
 14. The combination as defined in claim 10 further including meansmounting said rear wall for pivotal movement about an axis disposedintermediate the upper end lower edges thereof, such that the portion ofthe rear wall above said axis pivots forwardly and downwardly while thatportion below said axis moves rearwardly away from the base wall toprovide a dumping opening immediately below material engaged againstsaid rear wall, with said forward and downward movement of the portionof the rear wall above said axis tending to initiate dumping of materialfrom said dumping.
 15. The combination as defined in claim 14, wherein aportion of the base wall includes blade elements which facilitateinitiation of the dumping operation, as well as scrape the interiorsurfaces of said side walls.
 16. A scraper bowl construction for usewith a vehicle of the general type employed in the transporting of earthor other similar materials, said bowl construction being open at thefront end portion thereof to facilitate loading and comprising: a pairof spaced apart side walls; a base wall arrangement intermediate saidside wall for supporting said material, said base wall arrangementincluding means for selectively providing a dumping opening thereinadjacent the rearward portion of said bowl; and rear wall means closingthe rear portion of said bowl, And including a rear wall member disposedbetween said side walls having a lower portion thereof positionedadjacent a rear edge of said base wall arrangement when both are in aclosed condition, and means for effecting selective movement of saidrear wall member rearwardly and downwardly with respect to said sidewalls and said base wall arrangement to define an open condition forsaid rear wall means, wherein said lower portion of said rear wall ispositionable at selected levels for use in the grading of material beingemptied from said bowl.
 17. In a vehicle for transporting earth or othersimilar material, a scraper bowl construction having an open forward endportion through which material is loaded and comprising: a pair ofspaced side walls, a rear wall disposed intermediate said side walls toclose the rearward end portion of said bowl; and base wall structure forsupporting said material, said base wall including first and secondpanel members, having oppositely disposed free edges and adjacent edges,hingedly connected together, the free edge of said second panel memberbeing disposed forwardly toward said open end portion of the bowl withthe free edge of said first panel member being disposed rearwardlytoward said rear wall when said base wall is in a closed condition, suchthat said panel members provide flat surfaces for supporting material insaid bowl; means slidably connecting said first and second panels tosaid side walls proximate the free edges thereof; and operating meansfor moving said panels from the closed condition to an open condition bymoving each said free edge relative to said side walls and toward eachother while the hingedly connected edges of said panels move upwardly,to provide dumping openings on opposite sides of said panels when in theopen condition.
 18. A scraper bowl construction as defined in claim 17,wherein said operating means include a pair of bell crank arrangementsjournalled to the respective side walls of said bowl construction, eachsaid bell crank arrangement including a pair of arm elements, one saidarm element being disposed exteriorly of the associated side wall andthe other interiorly thereof, said interiorly disposed arm elementsbeing connected to one of said panel members proximate the hingedlyconnected edges, and said exteriorly disposed arm elements beingoperatively connected to a driven reciprocal member for producingrotative movement of said bell crank, which movement effects theoperation of said panel member.
 19. A scraper bowl construction asdefined in claim 17, wherein said means slidably connecting said panelsto said side walls, includes track means carried by said side walls, anelongate rod element carried by each side panel, a pair of carriagemembers rotatably engaged to the opposed ends of each rod elementexteriorly of said side walls, and bearing means carried by each saidcarriage member in rolling engagement with said track means.
 20. Ascraper bowl construction as defined in claim 17, further includingblade means on a lower portion of said rear wall and means mounting saidrear wall for retractive and vertical movement away from the rear edgeof the base wall structure, such that said vertical movement willdispose said blade means for engagement with material being dumped fromsaid bowl.
 21. A scraper bowl construction for use with the vehicle ofthe general type employed in the transportation of earth or othersimilar materials, said bowl construction being open at the front endthereof to facilitate loading and comprising: a pair of spaced apartside walls; a base wall arrangement intermediate said side walls forsupporting said material, said base wall including first and secondpanel members having adjacent edges hingedly connected together with theremote edges of said panels being slidably mounted to tracks on saidside walls, and means for operating said panels from a closed, materialsupporting condition with said remote edges positioned toward the frontand rear bowl portions, resPectively, to an open condition by movingsaid remote edges toward each other while said adjacent hinged edges aremoved upwardly, such that in the open condition, a pair of dumpingopenings are provided on opposite sides of said panel; and rear wallmeans including a rear wall member closing the rear portion of said bowlconstruction and having a lower portion thereof positioned adjacent theremote edge of the rearwardmost panel of said base wall when said basewall arrangement and said rear wall means are both in the closedcondition, and means for effecting selective movement of said wallmember rearwardly and downwardly with respect to said side walls andsaid base wall arrangement to define an open condition for said rearwall means, wherein said lower portion of the wall member ispositionable at selected levels for use in grading of material beingemptied from said bowl.
 22. A method of dumping earth or other materialfrom a scraper bowl, which bowl is of a type including a pair of spacedside walls, base wall structure comprised of a pair of panels havingadjacent edges hingedly connected together and remote edges slidablelongitudinally relative to said side walls, said remote edges beingdisposed toward the forward and rear bowl portions respectively, when inthe closed condition, and a rear wall section mounted for retractivemovement from a closed condition with its lower portion disposedadjacent the rearwardmost panel edge to an open condition; said methodcomprising the steps of: first moving said rear wall section rearwardlyaway from said base wall to provide a space defined by the rearward edgeof the base wall and the lower portion of said rear wall, through whichmaterial may be initially emptied from said bowl; and then moving bothsaid remote edges of the base wall panels relative to said side wallsand toward each other, while simultaneously moving said hingedlyconnected edge portions upwardly to define a pair of base wall dumpingopenings through which the remaining material in said bowl constructioncan be emptied.
 23. A method as defined in claim 22 wherein said step ofmoving the rear wall section rearwardly includes the step of moving saidsection downwardly with respect to said sidewalls to dispose thelowermost portion thereof in position for grading the material dumpedfrom said bowl.
 24. A method as defined in claim 23 wherein the mountingof said rear wall is achieved with a link arrangement pivotallyconnected to said rear wall and a rear frame portion of the bowlconstruction, thus defining a fixed and a floating pivot, and said stepsof moving the rear wall section rearwardly and downwardly include thestep of first pivoting said wall section and said link arrangement aboutthe fixed pivot to cause the lower portion thereof to move away from thebase wall, engaging said lower section against stop means to precludefurther retractive movement and then effecting relative pivotal movementbetween said link arrangement and said wall member about said floatingpivot to cause the entire wall member to move downwardly.
 25. A methodas defined in claim 24, wherein said steps of moving the wall sectionrearwardly and downwardly include the step of applying a retractingforce to said link arrangement at a location disposed below both saidfixed and said floating pivots.